CHAPTER XX. 

 SOLUTION OF THE WORLD-PROBLEMS. 



A glance at the progress of the nineteenth century in solving cosmic 

 problems. I. Progress of astronomy and cosmology. Physical 

 and chemical unity of the universe. Cosmic metamorphoses. 

 Evolution of the planetary system. Analogy of the phylogenetic 

 processes on the earth and on other planets. Organic inhabitants 

 of other heavenly bodies. Periodic variation in the making of 

 worlds. II. Progress of geology and palaeontology. Neptunism 

 and Vulcanism. Theory of continuity. III. Progress of physics 

 and chemistry. IV. Progress of biology. Cellular theory and 

 theory of descent. V. Anthropology. Origin of man. General 

 conclusion. 



At the close of our philosophic study of the riddles of 

 the universe we turn with confidence to the answer 

 to the momentous question, How nearly have we 

 approached to a solution of them ? What is the 

 value of the immense progress which the nineteenth 

 century has made in the knowledge of nature? And 

 what prospect does it open out to us for the future, 

 for the further development of our system in the 

 twentieth century ? Every unprejudiced thinker who 

 impartially considers the solid progress of our empirical 

 science, and the unity and clearness of our philosophic 

 interpretation of it, will share our view : the nine- 

 teenth century has made greater progress in know- 

 ledge of the world and in grasp of its nature than 

 all its predecessors ; it has solved many great 



373 



